HELP - AC problem - Honda 2000 CRV

We are having AC problems with a 2000 Honda CRV.

We just did a successful vacuum and leak test,
then recharged the system with 134a.

At a constant 3000 RPMs, and with a set of AC gages attached
to the low & high ports, the AC system does this:

1. The low pressure gauge rises in pressure until the high
limit (low side) switch disengages the AC clutch. The high pressure gauge
is within limits at this time.

2. When the low pressure gage returns to safe pressure, the AC
clutch engages. This time the high side pressure gage begins to climb
until it reaches the high side limit in PSI, and the AC clutch disengages.
The high side pressure declines to a safe PSI and the AC clutch
again engages. Now go back to #1 above and start the low pressure side
rising to the upper limit. It is a continuous loop.

The above is an endless loop of reaching max low PSI, shut off, reaching
max high PSI, shut off, reaching max low PSI, shut off ...

Even at a steady 3000 RPM, the above constant cycling does not do a
satisfactory job of cooling the car.

What's the problem?

THANKS,
Gene

 

Why did you have to vacuum your system? Did you make sure no air got into
the system by bleeding a little refigerant gas from the servicing lines?
Did the AC have a problem before all of your work? Did you put the
absolute correct amount of R-134A and oil into the system? The answers to
these questions may help us figure out what's going on here.

 

THANKS !!

The high pressure valve became defective and leaked out
the 134a. We replaced both valves, and the system is 100%
closed now.

refigerant gas from the servicing lines?
Yes, cleared all lines.

Yes, the very same problem. Pulling it down, checking for leaks, and
refilling it with two cans of 134a did not help. Still having the SAME
problems as when it was previously full of 134a. The leaking valve was
just a good time to try & fix it. (It's my kid's car.)

system?
I put in two cans, which should be more than enough. I was having the same
high pressure problem when putting in the two cans - had to do it over a
full day, so as to not exceed pressures on the low side. Not sure if I had
to do that, but it made me feel better

THANKS for al the kind assistance - I need it.


*******************

I'm pretty sure the problem is that the high pressure side immediatelly
rises and triggers the high pressure sensor. The question is, why
does the pressure on the high side rise, and keep going until it
trips the high pressure sensor?

Something clogged?
Bad compressor?

THANKS,
Gene

 

************ COPY ********

Thanks.

I agree with your best guess, that it could be some blockage on the high
side.

The car was recently purchased used by my kids, so we have no historical AC
data.

I did three similar AC compressor replacements with these same gauges in the
last month and all went 100% successfully - so I am pretty sure the gauges
are OK.

I pulled ~ 25-26 vacuum for ~ an hour with both low & high sides open.
That should have been enough to get the moisture.

Because I am doing it myself, here is the approach that I like, and will
probably
do in this case, assuming the problem persists.

1. Go to a local salvage yard & find the best AC compressor from a "wrecked"
car.
It must come from a reputable yard & have an unconditional 100% return for
90 days.
To test it, I pour in an ounce of the appropriate oil into the compressor,
turn it over by
hand to check compression a few times, then pour out the oil onto a clean
napkin.
It must have good compression & no foreign matter in the oil. Next I test
the clutch with
a 12VDC+ to the clutch pin. Finally, I spin the pulley and use a stethoscope
to listen
to the bearing free wheel. If all of the above are OK, I install said AC
compressor.
Here is my logic for the above:
a. Factory AC compressor are WAY too expensive.
b. The lower priced new compressors are made in China.
c. The rebuilt compressors are the patched trash that were returned.
d. The used ones per above are the only ones that are in good condition &
low priced. So far, I have never had a bad one. Just check them out first.


2. Buy all new O rings, seals, dryer, filter, etc. - I even replace the
low/high port valves.

3. Remove the old compressor, etc. & flush the system

4. Install the used compressor with oil, etc. , do a complete vacuum & leak
test - then
fill with 134a.

The TOTAL out-of-pocket cost runs from $100 to $250, depending on the car.

In that it is so inexpensive to just do it right, this is probably what is
best for this Honda.
It's really not worth the time and effort to trace down a potential clogged
point in the system
for $200 or so.

However, I really would like to know what the problem is with this Honda,
I'm just currious

THANKS,
Gene

 

************ COPY ********

Thanks.

I agree with your best guess, that it could be some blockage on the high
side.

The car was recently purchased used by my kids, so we have no historical AC
data.

I did three similar AC compressor replacements with these same gauges in the
last month and all went 100% successfully - so I am pretty sure the gauges
are OK.

I pulled ~ 25-26 vacuum for ~ an hour with both low & high sides open.
That should have been enough to get the moisture.

Because I am doing it myself, here is the approach that I like, and will
probably
do in this case, assuming the problem persists.

1. Go to a local salvage yard & find the best AC compressor from a "wrecked"
car.
It must come from a reputable yard & have an unconditional 100% return for
90 days.
To test it, I pour in an ounce of the appropriate oil into the compressor,
turn it over by
hand to check compression a few times, then pour out the oil onto a clean
napkin.
It must have good compression & no foreign matter in the oil. Next I test
the clutch with
a 12VDC+ to the clutch pin. Finally, I spin the pulley and use a stethoscope
to listen
to the bearing free wheel. If all of the above are OK, I install said AC
compressor.
Here is my logic for the above:
a. Factory AC compressor are WAY too expensive.
b. The lower priced new compressors are made in China.
c. The rebuilt compressors are the patched trash that were returned.
d. The used ones per above are the only ones that are in good condition &
low priced. So far, I have never had a bad one. Just check them out first.


2. Buy all new O rings, seals, dryer, filter, etc. - I even replace the
low/high port valves.

3. Remove the old compressor, etc. & flush the system

4. Install the used compressor with oil, etc. , do a complete vacuum & leak
test - then
fill with 134a.

The TOTAL out-of-pocket cost runs from $100 to $250, depending on the car.

In that it is so inexpensive to just do it right, this is probably what is
best for this Honda.
It's really not worth the time and effort to trace down a potential clogged
point in the system
for $200 or so.

However, I really would like to know what the problem is with this Honda,
I'm just currious

THANKS,
Gene